Submission #425902

#	Time	Username	Problem	Language	Result	Execution time	Memory
425902		dxz05	Crocodile's Underground City (IOI11_crocodile)	C++14	100 / 100	839 ms	53288 KiB

crocodile

#include "crocodile.h"
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define MP make_pair

const ll INF = 1e18 + 1e8;
const int N = 3e5 + 3e2;

vector<pair<int, int>> g[N];

ll dp[N];
bool processed[N];
int cnt[N];

pair<ll, ll> p[N]; /// p[i].first <= p[i].second

void upd(int i, ll x){
    vector<ll> v = {p[i].first, p[i].second, x};
    sort(v.begin(), v.end());
    p[i].first = v[0];
    p[i].second = v[1];
}

int travel_plan(int N, int M, int R[][2], int L[], int K, int P[]){
    for (int i = 0; i < M; i++){
        g[R[i][0]].emplace_back(R[i][1], L[i]);
        g[R[i][1]].emplace_back(R[i][0], L[i]);
    }

    for (int i = 0; i < N; i++){
        p[i] = MP(INF, INF);
        dp[i] = INF;
    }

    priority_queue<pair<ll, int>> pq;
    for (int i = 0; i < K; i++){
        dp[P[i]] = 0;
        pq.push(MP(0, P[i]));
        p[P[i]] = MP(0, 0);
    }

    while (!pq.empty()){
        int v = pq.top().second; pq.pop();
        if (processed[v]) continue;
        processed[v] = true;

        for (auto edge : g[v]){
            int u = edge.first, w = edge.second;

            upd(u, dp[v] + w);
            if (dp[u] > p[u].second){
                dp[u] = p[u].second;
                pq.push(MP(-dp[u], u));
            }
        }

    }

    //for (int i = 0; i < N; i++) cout << dp[i] << ' ';

    return dp[0];
}

/**
5 7 2
0 2 4
0 3 3
3 2 2
2 1 10
0 1 100
0 4 7
3 4 9
1 3
14
*/

• Subtask 1: 46 / 46
• Subtask 2: 43 / 43
• Subtask 3: 11 / 11